How Much Sugar is Really in that Soda?

[Moey]

My daughter is working on her science fair project on the amount of sugar in sodas and is unsure of how much water should be added to make the sugar solutions. She made all of the sugar solutions (5%, 10% etc) with 1.7L of water. She tried using 2L of water but the pop bottles overflowed. She is unsure is she made the solutions accurately b/c she has read to make a 5% solution she should use 5g of sugar with 100ml of water. However, this is not enough water to use the hydrometer to read the density. How much water should she add to make accurate solutions and be able to use the hydrometer as the experiment indicates? Thank you for your time and input.

[kgudger]

Hello and welcome to the forum!

If I read the experiment correctly, the proper way to make the solutions is to put the amount of sugar into the bottles first, then fill the 2L bottle up to the 2L mark. This will give you consistent sugar solutions.

If you don't want to make this much solution, you can pick the amount of solution you want (say 1L), and since water's density is 1g/ml, you can multiply the final solution amount (1000 ml) (times) (percentage sugar solution) to figure out how much sugar to add. Put the sugar in the container and then fill with water up to the desired level.

For example, for a 1.5L total solution of 5% sugar, you would have 1500 ml * 0.05 = 75 g of sugar, then fill with enough water to make 1.5L of solution.

Let us know if you have any other questions.
Keith